4196239 - GelMA-chitosan hydrogels as soil conditioners in agriculture

Soil conditioners, also referred to as soil amendments, help improve soil structure by increasing aeration, water holding capacity, and nutrients. Polyacrylamide, a commonly used synthetic soil conditioner, is a long-chain synthetic polymer that acts as water retention agent as well as a strengthening agent against erosion. However, polyacrylamide does not biodegrade in groundwater and can often be collected in runoff resulting in potential environmental and health concerns. Bio-derived soil conditioners are increasingly valued for enhancing agricultural sustainability and improving crop yield. We have developed Gelatin methacryloyl (GelMA)-chitosan hydrogels as a biodegradable alternative to conventional synthetic soil conditioners, with the dual purpose of improving soil moisture retention as well as pathogen resistance. GelMA is a non-toxic material with functional groups suitable for crosslinking and modification. Incorporating chitosan into GelMA enhances the swelling capacity of the hydrogels while contributing antimicrobial properties and promoting plant growth. Preliminary data indicates that GelMA-chitosan hydrogels exhibit improved swelling ratios compared to polyacrylamide-based gels. Scanning electron microscopy (SEM) indicates that the inclusion of chitosan helps form more uniform pore structure, potentially improving the hydrogel's ability to retain water and nutrients. Rheological studies are conducted to evaluate the stability of the hydrogels under mechanical stress, ensuring durability in field applications as a soil additive. Additionally, we have investigated the effects of varying concentrations of precursors on swelling, water retention, and average pore size of the hydrogel. Ultimately, these findings suggest that GelMA-chitosan hydrogels are promising and environmentally sustainable materials to be used as soil conditioners. We anticipate that these hydrogels will have the potential to improve crop yield while reducing the environmental impact of conventional agricultural practices.